Who hasn’t wished they could erase something from their memory, like an embarrassing mistake or the memory of last year’s rainy vacation? But is it possible to forget something on purpose?
Memories are not accurate reflections of reality. Only a fraction of what we experience makes its way into our memory, and most of the details are lost over time. New knowledge can overwrite old information. For example, if a friend gives us their new phone number, we soon forget the old one. Fortunately, unpleasant memories often fade or seem less bad in retrospect. Sometimes, we manage to reframe them in a positive light and recognize the good in what was otherwise an unpleasant experience.
Numerous studies have investigated whether we can actively control the process of forgetting. However, the results are complex. In principle, it seems possible to intentionally influence one’s memory. When people are shown an image and then asked to forget it shortly afterward, they often remember it less well later than people who are not given this request. These experiments offer insight into the underlying neural mechanisms: the lateral prefrontal cortex, located in the frontal lobe, inhibits the activity of the hippocampus, which is a key center for memory formation.
However, it is unclear whether deliberate forgetting is permanent. Forgetting does not necessarily mean that a memory trace is irretrievably erased. It is usually only suppressed, but remains in principle. Some of it returns later, even stronger.
Researchers have known about this effect for some time: as soon as I stop trying to push an unwanted thought out of my mind, the thought becomes more insistent. “Don’t think of a pink elephant.” With this instruction, it’s almost impossible to avoid thinking about a pink elephant. However, as soon as you stop trying, the pink elephant won’t leave your mind. Try it yourself.
Therefore, intentional forgetting can backfire. Memories that are most desperately needed, such as those of traumatic events, are often the most persistent. This is why repression has a bad reputation. Sigmund Freud’s psychoanalysis is based on this idea: people who avoid the shadows of the past may develop a psychological disorder.
However, this doesn’t mean we should dwell on every negative thought. It’s often quite helpful to put troubling thoughts aside for a while. There is now evidence suggesting that the ability to suppress memories helps cushion the effects of stress in the long run. But that doesn’t mean the content in question simply disappears. At some point, you may have to confront it.
